Alloys of titanium containing beta stabilizers with minor amounts of aluminum



ALLOYS OF TITANIUM CONTAINING BETA STA- BILI%JIIEVIIZS WITH MINOR AMOUNTS ,OF ALU- Willlam W. Gullett, College Park, Md., asslgnor to Chicago Development Corporation, Riverdale,Md., a corporation of Delaware i No Drawing. Application June 25, 1957 Serial No. 667,963

2 Claims. (Cl. 75-1755) This invention relates to fabricated alloys of titanium with beta stabilizing elements having from .01%-.03% oxygen and from .1-l% aluminum. In my copending application executed June 13, 1957, I have disclosed that alloys of titanium with l5% Fe, Cr, Mo, V and Mn with less than .03% oxygen having new and useful mechanical properties.

This invention relates to the modification of those properties by the addition of small amounts of aluminum. In my copending application referred to, I have disclosed that increasing the alpha stabilizing element oxygen above .03% rapidly brings the alloys of that invention into the range of conventional mechanical properties. The addition of substantial percentages of the alpha stabilizing element aluminum also brings the alloys of my previous invention into the range of mechanical properties of conventional alloys. I have found, however, that the addition of from 0.l-l% aluminum to the alloys of my earlier invention provides a heretofore unavailable combination of properties.

This may be conveniently illustrated by a specific example. An alloy of titanium with 4% vanadium made in accordance with my previous invention and fabricated to obtain a sheet containing .02% had the following properties when annealed at 800 C. and furnace cooled.

UTS, lbs./ YS. lbs./ Elana, Sq. In. Sq. Percent,

.294, ofiset ln2 I now make alloy sheet identical with the previous sheet except that it contains 5% aluminum. The properties are as follows when annealed at 800 C.

UIS. lbs./ YS, lhs./ Elong.

Sq. in. Sq. ln., Percent,

.27 oflset in 2 alloy is greatly increased, the properties of the quenched alloy being:

U'IS, lbs./ YS. lbs./ Elong Sq. ln. sq. in. Percent,

.2% ofiset in 2" It will be seen that the strength of the annealed alloy has been lowered to provide a cold workable alloy while tergrowths can be conveniently prepared 2,865,742 Puss es" D ta. as; {1953 ductility remains, at a far higher level than could be obtained with conventional alloys at the same. strength level and also higher than with-the substantially beta alloys of my previous invention. Quenching provides a hard strong alloy. I have found that the presence of aluminum in titanium alloys greatly increases the rate of oxygen absorption when heated in an atmosphere containing oxygen. In the practice of my invention, itis therefore necessary to avoid heatingthe'aIloy-without protection from oxygen and nitrogen." This may done by applying a suitable coating.

Example I I take crystal intergrowths of pure titanium-manganese alloy containing 4% manganese, less than .0l% oxygen and substantially no other impurities. Such crystal in according to the method disclosed in my copending application of even date.

I mix these intergrowths with 1% pure aluminum and form the mass into a consumable electrode. I melt the alloy into an ingot in a vacuum arc furnace. I fabricate the resulting ingot without substantial addition of oxygen and obtain a fabricated alloy analyzing 3.95 Mn, .015 oxygen and 1% Al, balance substantially. titanium. The alloy had the following properties:

UIS, lbs./ YS, lbs./ Elong., Sq. in. Sq. in., percent,

.2% offset in 2" Annealed, 800 C 135, 000 115, 000 36 Quenched, 900" C 228, 000 215, 000 11 Example 11 I take crystal intergrowths of titanium containing .5 iron. I form these into a consumable the addition of .25 Al and melt in avacuum arc furnace. The resulting ingot is fabricated to produce sheet analyzing 51% Fe, .24% Al, .01% O balance substantially titanium. This sheet hadthe following properties:

In this example, I take pure chromium, substantially free from oxygen, crystal intergrowths of pure titanium and pure aluminum. 1 form these into a consumable electrode and melt in a vacuum. The resulting ingot is worked into sheet and the sheet analyzed:

Percent Cr 3.1 O, .005 Al 1 Balance substantially titanium.

This sheet had the following properties:

U'IS. lbs./ Elong., Sq. in. 2 pageant,

Annealed, 800 0 120.000 110.000 30 quenched, 000 0 1 225,000 200, 000 8 Example IV vIn this example, I take crystal intergrowths of titanium with 2% molybdenum. I make these into a consumable electrode with i 6 .00000 with 0.25% pure aluminum. I work the resulting ingot into inch rod. The rod analyzes:

Percent Mo 1.9 5 O; .01 Al .25

This rod had the following properties:

UTS,lbs.l Ys lbs Elong., 10

s .m. t, Sq. 111., i gli Annealed, 800 0.--, 105,000 90, 000 30 QuenchedJOOF'O 185,000 160,000 15 4 15 What is claimed is: 1. Fabricated alloys of titanium with .15% of a metal selected from the group consisting of Fe, Cr, V, Mo and Mn, .01-.03% oxygen and .l-1% aluminum balance substantially titanium.

2. The method of heat treatment of alloys according to claim 1 which consists in heating at 800-900 C. and slow cooling whereby to soften the alloy mechanically working in the softened state, heating the alloy to 800- 900 C. and cooling rapidly, whereby to harden and strengthen the alloy. r

References Cited in the tile of this patent UNITED STATES PATENTS 

1. FABRICATED ALLOYS OF TITANIUM WITH .1-5% OF A METAL SELECTED FROM THE GROUP CONSISTING OF FE, CR, V, MO AND MN, .01-.03% OXYGEN AND .1-1% ALUMINUM BALANCE SUBSTANTIALLY TITANIUM. 